Recently found out that such a surgery would cost 100,000฿ at the government hospital. Doctors wanted to add the cost of a more expensive lens, adding another 30,000฿.
A friend arranged a visit to the Udon Eye Clinic, where the doctor spoke English and answered all my questions.
The reason for government hopital high prices, more than double (x2.5) for foreigners is because nationals from nearby countries were taking advantage of Thailand's low medical prices and overburdening the system.
That is probably not going to help Thailand's medical tourism.
The big difference between lenses is the cheaper lens has only one focus and requires reading glasses for near sight. The more expensive lens focuses near and far. The optometrist recommended both eyes should have identical lenses to minimize future problems.
Needless to say I will be having Cataract surgery in Udon at lesser cost than quoted here in Sakon Nakhon